The ADA has the info. All OMFS residencies submit a mandatory yearly summary of their stats, ie # of orthognathic jaws, sedations, cosmetics, trauma, etc. A lot of it is even divided into types, like how many frontal sinus fractures, how many ZMC's, etc.
Now, can you get your hands on it? The only way I know is to ask it of each program. The OMS program director at my dental school told me that if a program is reluctant to show that information to you then its one you want to avoid.
Having said that only about 1/2 of the places I interviewed at would give the info.
Best Wishes.